1. Field of Invention
The invention relates to a solar cell and a method of manufacturing the same, and more particularly to a solar cell formed by one screen printing process, one firing process and one grinding process, or formed by two screen printing processes and two firing processes, and a method of manufacturing the same.
2. Related Art
A solar cell is an opto-electronic element for converting solar energy into electric energy. The solar cell is also referred to as a photovoltaic battery from the physical point of view.
The conventional solar cell is manufactured by providing a silicon substrate, and forming an anti-reflection coating (ARC) layer on the silicon substrate by way of chemical vapor deposition (CVD), such as plasma enhanced CVD (PECVD), and then the screen printing and co-firing processes are performed to form finger electrodes on the ARC layer. According to this manufacturing method, the co-firing temperature has to be very high so that the manufacturing cost cannot be decreased and the manufacturing time cannot be shortened.
Alternatively, after the ARC layer is formed, windows may be formed by way of etching, and then the silver paste is filled into the windows by way of screen printing so that the finger electrodes can be formed. According to this manufacturing method, the very high precision alignment is required. That is, the silver paste has to be precisely filled into the windows during the screen printing process. In order to solve the problem of alignment, the trade-off between the sizes of the windows and the efficiency of the solar cell has to be considered.
Therefore, it is an important subject of the invention to provide a solar cell, which is free from encountering the problem of alignment, and a method of manufacturing the solar cell with the lowered firing temperature.